Abstract
Not only endodontic treatment, but also in all dental fields, advances in treatment methods and instruments and
equipment continue. The size, shape, and orientation of the open cavity should be determined based on an understanding of
the curvature of the root canal to be treated, the degree of stenosis, the amount of opening of the patient, the skill of the opera-
tor, and the characteristics of the instruments and equipment used. The NiTi file made of martensite phase is less likely to cause
transport and has excellent root canal followability due to its shape memory effect. There is no file system that can be said to
use this file system to handle all cases. Continuously collect information on new file systems and understand the characteristics
of those file systems. It is important to use the new file system properly.
